Doorknob



FIG. 1 is a back view of a doorknob of the new design;

FIG. 2 is a top view of the doorknob of FIG. 1, the bottom view being identical;

FIG. 3 is a front view of the doorknob of FIG. 1;

FIG. 4 is a perspective view of the doorknob of FIG. 1;

FIG. 5 is a back view of a second embodiment of a doorknob of the new design;

FIG. 6 is a top view of the doorknob of FIG. 5, the bottom view being identical;

FIG. 7 is a front view of the doorknob of FIG. 5; and,

FIG. 8 is a perspective view of the doorknob of FIG. 5.

The portions of the Figures shown in phantom lines are not part of the claimed design but are for illustration only. 

The ornamental design for a doorknob, as shown and described. 